public class Black {
    public static void main(String[] args) {
        String str ="address";
        String str1=str.replace('a','A');//大A替换a
        String num1="45875449";
        boolean b=num1.startsWith("45");//判断是否以45开头
        boolean c=num1.startsWith("42");//判断是否是42开头
        boolean d=num1.endsWith("49");//是否49结尾
        boolean e=num1.endsWith("68");//是否68结尾
        System.out.println(str1);
        System.out.println(b);
        System.out.println(c);
        System.out.println(d);
        System.out.println(e);



    }
}
